2. Dione's favorite exercise machine is a stair climber. On the "random” setting, it changes speeds at regular intervals, so the total number of simulated "floors" she climbs varies from session to session. Dione also exercises for different
lengths of time each session. She decides to explore the relationship between how long she works out on the stair
climber in minutes) and the number of floors it tells her that she has climbed. Dione records minutes of climbing
time and number of floors climbed for six exercise sessions. Computer output and a residual plot from a linear
regression analysis of the data are shown below.
3
Predictor Coef
Constant -3.822
Workout time 5.2150
(min)
SE Coef
5.458 -0.70
0.2779 18.76
P
0.522
0.000
2 -
1
Residual
S - 2.3472
R-Sq - 98.98 R-Sq(adj) = 98.68
0
-1 -
.
-2
15.0
25.0
17.5 20.0 22.5
Workout time (min)